While most years we only see a handful of swine variant cases, in the summer of 2012 we saw in excess of 300 cases spread across several states, nearly of which were linked to attendance and swine exposure at state and county fairs.

With fair season underway, and agricultural exhibits always very popular, the CDC has been promoting basic precautions for fairgoers via their twitter account.

Pigs can be infected with their own influenza viruses (called swine influenza) that are usually different from human flu viruses.

While rare, influenza can spread from pigs to people and from people to pigs. When people get swine flu viruses, it’s usually after contact with pigs. This has happened in different settings, including fairs. The Centers for Disease Control and Prevention (CDC) is concerned about a flu virus that has been found in U.S. pigs and that has infected people too. This virus – called H3N2v – may spread more easily from pigs to humans than is usual for swine flu viruses.

CDC Recommendations For People with High Risk Factors:

Anyone who is at high risk of serious flu complications planning to attend a fair where pigs will be present should avoid pigs and swine barns at the fair.

People who are at high risk of serious flu complications include children younger than 5 years, people 65 years and older, pregnant women, and people with certain long-term health conditions (like asthma and other lung disease, diabetes, heart disease, weakened immune systems, and neurological or neurodevelopmental conditions).

CDC Recommendations for People Not at High Risk:

Don’t take food or drink into pig areas; don’t eat, drink or put anything in your mouth in pig areas.

Take protective measures if you must come in contact with pigs that are known or suspected to be sick. This includes minimizing contact with pigs and wearing personal protective equipment like protective clothing and gloves and masks that cover your mouth and nose when contact is required.

Wash your hands often with soap and running water before and after exposure to pigs. If soap and water are not available, use an alcohol-based hand rub.

To further reduce the risk of infection, minimize contact with pigs in the pig barn and arenas.

Watch your pig (if you have one) for illness. Call a veterinarian if you suspect illness.

Avoid contact with pigs if you have flu-like symptoms. Wait 7 days after your illness started or until you have been without fever for 24 hours without the use of fever-reducing medications, whichever is longer. If you must have contact with pigs while you are sick, take the protective actions listed above.

People with high risk factors who develop flu symptoms should call a health care provider. Tell them about your high risk factor and any exposure to pigs or swine barns you’ve had recently. Seasonal flu vaccine will not protect against H3N2v, but prescription influenza antiviral drugs can treat H3N2v illness in people.

We’ve not seen sustained or efficient spread of these swine flu viruses in humans - but like all flu viruses - swine variant viruses
are
capable of evolving, reassorting, and adapting to their hosts.

They described both of these novel subtypes as “. . . virulent
and can sustain onward transmission in pigs, and the naturally
occurring mutations in the HA were associated with antigenic divergence
from H3 IAV from human and swine’” and goes on to warn that ``. . . the potential risk of these emerging swine IAV to humans should be considered”.

While North American swine variant viruses are a legitimate concern, globally - particularly in places where surveillance and biosecurity is lax - the risks are arguably even greater.

Our study shows the potential of
EAH1N1 SIVs to transmit efficiently in humans and suggests that
immediate action is
needed to prevent the efficient
transmission of EAH1N1 SIVs to humans.

And just last March, inWHO: H1N1v Cases In China, we looked at recent reports of human H1N1v infection and the WHO's Risk Assessment.

Risk Assessment:1.What is the likelihood that additional human cases of infection with influenza A(H1N1)v viruses will occur?Influenza A(H1N1) viruses circulate in swine
populations in many regions of the world. Depending on geographic
location, the genetic characteristics of these viruses differ. Most
human cases are exposed to the A(H1N1) virus through contact with
infected swine or contaminated environments. Human infection tends to
result in mild clinical illness. Since these viruses continue to be
detected in swine populations, further human cases can be expected.

The 2009 H1N1 pandemic showed how it can take years, sometimes even decades, of a virus kicking around in swine herds before it evolves enough to spark a public health threat.